An embodiment of the present invention provides a phase shifter, comprising: a base dielectric layer; a tunable dielectric layer overlaying at least a portion of the base dielectric layer; and at least two conductors overlaying at least a portion of the tunable dielectric layer, the at least two conductors positioned so as to form a slot-line topology. In an embodiment of the present invention the slot-line may be between 2 μm and 5 μm wide and the tunable dielectric layer may be between 0.3 μm to 1.5 μm thick. Further, the slot-line topology may be a uniform slot-line topology throughout the length of the at least two conductors and the slot-line topology may have an edge ratio defined by r=Llow/(Llow+Lhigh). The edge ratio may be optimized for minimizing metal loss and minimizing dielectric loss for a given phase shifter length. In an embodiment of the present invention the value of r may be between 0.1 and 0.2.